1. Field
Exemplary embodiments relate to a semiconductor device, and more particularly, to a semiconductor device using a Replacement Metal Gate (RMG) process and a method for fabricating the same.
2. Description of the Related Art
An electronic device is realized using a plurality of transistors, and the transistors continue to be scaled down. Although transistors are scaled down in size, the performance of the transistors has to be improved. To this end, a gate structure including a high-k material and a metal gate electrode is being suggested.
The metal gate electrode requires a work function metal to modulate the threshold voltage of a transistor. However, since the work function metal is vulnerable to subsequent thermal treatment, there is a limitation in increasing the threshold voltage of the transistor.